Kato, N. et al, Nature, 2016, Accelerated Article Preview. Celeste Alverez Current Literature 9/10/ /10/2016 Celeste Wipf Group 1

Size: px

Start display at page:

Download "Kato, N. et al, Nature, 2016, Accelerated Article Preview. Celeste Alverez Current Literature 9/10/ /10/2016 Celeste Wipf Group 1"

Paulina Tucker
6 years ago
Views:

1 Kato, N. et al, Nature, 2016, Accelerated Article Preview Celeste Alverez Current Literature 9/10/2016 9/10/2016 Celeste Wipf Group 1

2 Malaria Caused by Plasmodium parasites Carried by species of the Anopheles genus mosquitos 2 types: Uncomplicated Symptoms are flu-like including fever, sweats, neausea/vomiting, chills, headaches, bodyaches Severe Complicated by organ failure, blood or metabolism abnormalities Including anemia, kidney failure, cerebral malaria, hypotension, acute respiratory distress syndrome, hyperparasitemia (>5% of blood cells are infected with parasite Can relapse depending on the type of parasite causing the initial infection (due to dormant parasite living in liver) 9/10/2016 Celeste Wipf Group 2 Malaria CDC,

Malaria parasite life cycle 9/10/2016 Celeste Alverez @ Wipf Group 3

3 Malaria parasite life cycle 9/10/2016 Celeste Wipf Group 3 Malaria NIAID,

Parasites 5 malaria causing parasites that infect humans P.

knowlesi (typically infects macaques, but can infect humans;

4 Parasites 5 malaria causing parasites that infect humans P. falciparum (causes severe form, found worldwide in tropical/subtropical areas) P. vivax (can lead to relapse, found mostly in South America and Asia, some in Africa) P. ovale (can lead to relapse, found mostly in Africa and western Pacific islands) P. malariae (can lead to chronic malaria, found worldwide) P. knowlesi (typically infects macaques, but can infect humans; found in Southeast Asia, 24-replication cycle) P. falciparum P. vivax P. ovale P. malariae P. knowlesi 9/10/2016 Celeste Wipf Group 4 Malaria CDC,

World Distribution Estimated 214 million cases in 2015 9/10/2016 Celeste

5 World Distribution Estimated 214 million cases in /10/2016 Celeste Wipf Group 5 Malaria CDC,

6 Current Standard of Care Typically effective against blood-stage parasite (the form causing active disease) Need drugs effective at all stages of life cycle 9/10/ Malaria CDC,

7 Compound Identification 1. ~100,000 compounds screened against a multi-drug resistant strain of P. falciparum (Dd2) for inhibition of blood-stage parasite growth 2. Counter-screened against a panel of parasite isolates and drug-resistant clones to deprioritize compounds with known mechanisms of action Including screening efficacy in liver-stage and transmissionstages 4 series were found: 9/10/2016 7

8 Activity of Compounds with Known Targets 9/10/2016 Celeste Wipf Group 8

9 BRD3444 Shows submicromolar potency at 3 stages of P. falciparum life cycle 9/10/2016 Celeste Wipf Group 9

10 BRD3444 MOA Developed mutant lines resistant to BRD1095 Found a singlenucleotide variant in the α-subunit of phenylalanyl-trna synthetase (PfcPheRS) PheRS is new target for antimalarial treatment 9/10/2016 Celeste Wipf Group 10

11 BRD3444 Synthesis 9/10/2016 J. Org. Chem. 2012, 77, Kato, N. et al, Nature, 2016, Accelerated Article Preview

12 SAR 9/10/2016 Celeste Wipf Group 12

13 SAR 9/10/2016 Celeste Wipf Group 13

14 BRD7929 vs. BRD3444 9/10/2016 Celeste Wipf Group 14

15 BRD7929 vs. BRD3444 * PK in CD-1 mice PK in P. falciparum (3D7HLH/BRD) infected NSG mice IV determined in a separate assay over 72 h to determine T1/2 t = 24 h #t = 72 h F (%) based on initial IV study at 24 h 9/10/2016 Celeste Wipf Group 15

16 Efficacy of BRD7929 in blood-stage Single dose curing in a humanized mouse model of blood-stage infection 9/10/2016 Celeste Wipf Group 16

17 Efficacy of BRD7929 in liver-stage Blood-stage biomarker also not present in blood Suggests elimination of dormant liver-stage infection 9/10/2016 Celeste Wipf Group 17

18 Efficacy of BRD7929 in transmission-stage Marker not detectable after 7 days Suggests the use as prophylaxis to prevent transmission of malarial parasites 9/10/2016 Celeste Wipf Group 18

19 Safety of BRD7929 BRD7929 shows moderate cytotoxicity in select cell lines and herg inhibition at 2.21 um BRD3316 shows much better safety profile but is 4-fold less potent against Pf Dd2 (no other data shown) 9/10/2016 Celeste Wipf Group High dose study of BRD7929 (100 mg/kg) shows no adverse effects in organs shown 19

20 Conclusions Utilizing a diversity-oriented synthesis generated 4 new inhibitors of malarial parasites A bicyclo azetidine (BRD3444) was found to inhibit parasite growth through a previously unknown malarial target (PfcPheRS) After SAR exploration BRD7929 was found to eliminate bloodand liver-stage P. falciparum infection in a humanized mouse model with a single dose BRD7929 was also found to apparently prevent transmission possibly allowing for use as a prophylactic against P. falciparum with a single dose The safety profile needs to be further explored, however initial high dose tests suggest tolerability Resistance was unable to be forced over 60 days while the known antimalarial atovaquone acquired resistance during this same time 9/10/2016 Celeste Wipf Group 20

Symptoms of Malaria. Young children, pregnant women, immunosuppressed and elderly travellers are particularly at risk of severe malaria.

Symptoms of Malaria. Young children, pregnant women, immunosuppressed and elderly travellers are particularly at risk of severe malaria. Preventing Malaria 1 Malaria is the world s most prevalent parasitic disease, accounting for an estimated 216 million cases with 655,000 deaths annually. Many people acquire malaria during travel to tropical